I wanted to start a new thread as to not hijack the other thread about E8's. http://frisco.org/shipit/index.php?threads/redbird-e8s.13269/page-2 Karl wrote: "The Ash Grove Sub had APBS signals before the CTC was installed. Within the context of this discussion, it was not a dark railroad...." What is this APBS signal and how is it different that CTC? Any ideas on when the APBS system would have been installed on the Ash Grove Sub? Thanks, Ethan
During 1908, the Frisco-RI System contracted with US&S to install the new ABS system. On the Frisco portion that was KC- B ‘ham and St Louis - OKC. Most was in place by 1909, and I believe the job was complete by 1910. APBS and OBS, both of which have been discussed in detail on this site, are automatic block signal system, which indicate block occupancy. The signals do not govern movement, but convey only the occupancy of the block(s) ahead. The ETT and train orders govern all movements. CTC is a system in which the dispatcher can remotely control A (absolute)-block signals and power switches. Under CTC rules, the indication of the signal governs train movements.